Radio Rock is home to a host of flamboyant and colourful DJs. Who do you play?
Rhys: "My character is Angus "The Nut" Nutsford. He's predominantly the wacky, comedy DJ. He's a bit left of field so he stands out from the others."
Chris: "I play simple Simon Swafford who is a breakfast jock on Radio Rock. He's a very positive guy, very loveable, very romantic but a bit of a loser in love."
The movie boasts a fairly large ensemble cast. Where do your characters fit in relation to the other DJs?
Rhys: "Angus is not as cool or as into his music, so he gets picked on a little bit. Some of them find him a bit annoying and if the boat was sinking and they were saving each other and one guy had to get left behind, I think it would be him!"
Chris: "At times Simon is the fall guy, at times he lifts their spirits. He's the sweet one, when it comes down to it. He's the guy who will love you regardless."
Neither of you are from the UK, so how much knowledge did you have of pirate radio stations before this movie?
Rhys: "We had a pirate station in New Zealand, so I knew of them and their existence. At one point there were up to eight boats outside the legal limit blasting music out, then Radio 1 started and all the pirates seemed to get jobs there and music went mainstream."
Chris: "My parents had told me a bit, but it wasn't the same in Ireland so I looked up broadcasts on YouTube and other things, which was great. It was such a fun time and there was so much freedom on the airwaves."
We see you actually DJing in the movie. How did you prepare for the technical side of the challenge?
Rhys: "We got trained by an ex-pirate from the sixties who showed us how the equipment worked. It was a lot more hands on in those days, these days it's all turn on the computer and 'oh, the playlist is already there - see you for lunch!'"
Chris: "I went to watch a few shows to see how people operated around the microphone, which was interesting because they were all very different. Like, Chris Moyles was very casual, standing up through his whole show and Chris Evans was very business-like and organised."
You worked in a mock radio station before filming, but did you have any prior experience on the airwaves?
Rhys: "I briefly did a six-week course where you learned stuff about DJing and at the end you got a certificate with a DJ name. Mine was DJ Joka and unfortunately I never worked! In the film, I took over the DJ side for Angus and wrote my own comedy set for him. Each actor got shot for an hour doing a DJ set and then those bits were used throughout the film."
Were you nervous about spending 14 weeks filming on a ship in the middle of the North Sea?
Rhys: "I actually went to sailing camp when I was younger and remember being in a little tiny boat learning to sail. Being from New Zealand, we're very boat orientated so it wasn't a problem. No sea sickness, even being thrown in the ocean was fine!"
Chris: "I'd never been at sea, apart from maybe a little ferry ride. I was a bit worried about being seasick but, if anything, I was landsick! When I got off the boat I would vomit a lot. Why? I couldn't face the bloody earth anymore!"
To prepare for the filming conditions, you were sent to a "boat camp" before production started. What exactly did that entail?
Rhys: "We got to hang out, drink a few beers, watch some movies, listen to rock and roll and just experience what it was like living in tight quarters with people who have different personalities."
Chris: "It was really good to get used to working on a ship and also learning what the other actors' sensibilities were and so on, for when you're improvising during a scene."
Finally, if you put a bunch of comedians on a boat in the middle of the North Sea, there must have been some good practical jokes?
Rhys: "By magic, we all got on! So, we all shared our time equally making each other laugh."
Chris:"The ship we use in the film is a rescue ship and it had a morgue on the lower decks. Myself and Rhys Ifans were the first people on board and we decided to play a little joke on the girls. I decided to hide under a sheet in the morgue and hurl myself at them. Incredible that it worked, the man under a sheet joke is so twenties!"
The Boat That Rocked opens in the UK on April 3.